618 



ANGIOLOGY 



Relations. Within the pelvis, it lies in front of the Piriformis muscle, the sacral plexus of 

 nerves, and the inferior gluteal artery. As it crosses the ischial spine, it is covered by the Glutaeus 

 maximus and overlapped by the sacrotuberous ligament. Here the pudendal nerve lies to the 

 medial side and the nerve to the Obturator interims to the lateral side of the vessel. In the peri- 

 neum it lies on the lateral wall of the ischiorectal fossa, in a canal (Alcock's canal) formed by the 

 splitting of the obturator fascia. It is accompanied by a pair of venae comitantes and the pudendal 

 nerve. 



Peculiarities. -The internal pudendal artery is sometimes smaller than usual, or fails to give 

 off one or two of its usual branches; in such cases the deficiency is supplied by branches derived 

 from an additional vessel, the. accessory pudendal, which generally arises from the internal 

 pudendal artery before its exit from the greater sciatic foramen. It passes forward along the 

 lower part of the bladder and across the side of the prostate to the root of the penis, where it 

 perforates the urogenital diaphragm, and gives off the branches usually derived from the internal 

 pudendal artery. The deficiency most frequently met with is that in which the internal pudendal 

 ends as the artery of the urethral bulb, the dorsal and deep arteries of the penis being derived 

 from the accessory pudendal. The internal pudendal artery may also end as the perineal, the 

 artery of the urethral bulb being derived, with the other two branches, from the accessory vessel. 

 Occasionally the accessory pudendal artery is derived from one of the other branches of the 

 hypogastric artery, most frequently the inferior vesical or the obturator. 



Branches. The branches of the internal pudendal artery (Figs. 542, 543) are: 



Muscular. Artery of the Urethral Bulb. 



Inferior Hemorrhoidal. Urethral. 



Perineal. Deep Artery of the Penis. 



Dorsal Artery of the Penis. 





Posterior scrotal arteries 

 Posterior scrotal nerves 



Pudendal nerve 

 Internal pudendal artery 



FIG. 542. The superficial branches of the internal pudendal artery. 



The Muscular Branches consist of two sets: one given off in the pelvis; the other, 

 as the vessel crosses the ischial spine. The former consists of several small offsets 

 which supply the Levator ani, the Obturator internus, the Piriformis, and the 

 Coccygeus. The branches given off outside the pelvis are distributed to the 

 adjacent parts of the Glutreus maximus and external rotator muscles. They 

 anastomose with branches of the inferior gluteal artery. 



